Question

look at this diagram: if jl and mo are parallel lines and m∠lkn = 128°, what is m∠jkn?

Explanation:

Step1: Recall angle - sum property

$\angle LKN$ and $\angle JKN$ are a linear - pair of angles. The sum of angles in a linear pair is $180^{\circ}$.
Let $m\angle JKN=x$. Then $m\angle LKN + x=180^{\circ}$.

Step2: Substitute the value of $\angle LKN$

Given $m\angle LKN = 128^{\circ}$. Substitute into the equation: $128^{\circ}+x = 180^{\circ}$.
Solve for $x$: $x=180^{\circ}-128^{\circ}$.
$x = 52^{\circ}$.

Answer:

$52^{\circ}$